Anaemia Flashcards
How do stem cells turn into B or T lymphocytes?
Lymphoid stem cell > lymphoblast > lymphocyte > B or T lymphocyte
B cells mature in bone marrow
T cells mature in thymus
How to blood stem cells turn into Granulocytes?
Myeloid stem cell > myeloblast > granulocyte > neutrophil, eosinophil, basophil
how to blood stem cells turn into macrophages?
Blood stem cell > monoblast > monocyte > agranulocyte that becomes fixed to a tissue to become macrophage.
how do blood stem cells turn into erythrocytes?
blood stem cell > myeloid stem cell > erythroblast > erythrocyte (RBC)
How do blood stem cells turn into platelets?
Blood stem cell > myeloid stem cell > thromboblast > thrombocyte (platelet)
What is anaemia?
Anaemia is reduced blood cell mass.
It is a reduction in one or more of the major red blood cells (RBC) measurements obtained as part of the full blood count (FBC).
There is a reduction in O2 carrying capacity of blood with resultant reduced O2 delivery to tissues.
What are the two main measurements obtained as part of the full blood count (FBC)?
- Haemoglobin concentration (Hb)
> Males 130-170 g/L
> Females 120-150 g/L - Haematocrit (Htc)
> Males 0.4-0.54 L/L (40-52%)
> Females 0.37-0.45 (37-45%)
What is haematocrit?
Packed cell volume
- Vol of blood that consists of intact RBCs
What are the symptoms of anaemia? (3 categories)
- Neurological
- CVS
- Musculoskeletal
What are the neurological symptoms of anaemia?
Dizziness, fainting, lack of concentration, blurred vision, paraesthesia (peripheral), insomnia, irritability, depression.
What are the CVS symptoms of anaemia?
Chest pain (angina), shortness of breath, palpitations, intermittent claudication, heart failure (high output cardiac failure).
What are the musculoskeletal symptoms of anaemia?
Fatigability, tiredness, muscle cramps.
What are the signs of anaemia?
Pallor Tachycardia, bounding pulse, arrhythmias Postural hypotension Cardiac failure Systolic flow murmur Confusion Specific anaemias > Koilonychia (ferritin deficiency anaemia) > Jaundice (haemolytic anaemia) > Leg ulcers (sickle cell anaemia) > Bone deformities (thalassaemia)
What are the oral signs of anamaeia? (4)
- Atrophic glossitis - tongue smooth and depapilliated. looks shiny and smooth
- Angular colitis - red cracks at corners
- Aphthous ulcers - circular grey/yellow base with red halo. Worse and more frequent ulcers.
- Pseudomembranous candidiasis - epithelial cells more fragile, prone to colonisation of commensal organisms.
What is mean cell volume?
The size of red blood cells.
What are the different sizes of red blood cells? (3)
What is their MCV?
Microcytic - <83fl
Normocytic - 83-96fl
Macrocytic - >96fl
What are the different classes of anaemia? (3)
Microcytic
Normocytic
Macrocytic
Name the types of microcytic anaemia (4)
- Ferritin deficiency
- Thalassaemia
- Anaemia of chronic disorder
- Sideroblastic anaemia
Name the types of normocytic anaemia (4)
- Haemorrhage
- Haemolytic anaemia
- Anaemia of chronic disorder
- Bone marrow failure
What are the 2 types of macrocytic anaemia?
Megaloblastic and non-megaloblastic
Name the types of macrocytic anaemia.
Megaloblastic:
- Vit B12 deficiency
- Folate deficiency
Non-megaloblastic:
- alcohol
- liver disease
- hypothyroidism
- Aplastic anaemia
Name the types of megaloblastic macrocytic anaemia
Vitamin B12 deficiency
Folate deficiency
What is anaemia of chronic disorder?
Anaemia of chronic disorder occurs alongside chronic conditions e.g. tuberculosis, SLE, Crohn’s disease.
It is due to increased inflammatory cytokines e.g. IL-1, TNF-a. These reduce the RBC survival time.
What technique can help with identification of type of anaemia?
Blood film
What causes ferritin-deficiency anaemia? (4)
- Poor dietary intake of iron
- Reduced iron absorption
- Increased physiological demands
- Increased blood loss - CHRONIC BLOOD LOSS
What food contains high levels of iron?
liver, meat, beans, nuts, dried fruit (i.e. apricots), wholegrains, dark leafy greens.
What causes reduced iron absorption
Gastritis, coeliac disease, gastric bypass surgery.
What causes increased physiological demand (ferritin deficiency anaemia)?
Infancy, puberty, pregnancy
What causes increased blood loss (ferritin deficiency)?
haematemesis, melaena, haemoptysis, severe menorrhagia, gross haematuria.
Name some clinical manifestations specific for ferritin deficiency anaemia.
Appetite for ice.
Beeturia - ingestion of beets leads to red urine.
Restless leg syndrome
What do you look for in a history to find an underlying cause for ferritin deficiency anaemia?
GI blood losses
History of gastric or duodenal ulcer disease, H pylori infection, oesophageal varices.
Family history of bleeding disorders. - von willebrand disease. - hereditary hemorhagic telongiectasia.
Family history of chronic malignancy or symptoms suggestive of colonic malignancy.
Multiple blood donations
Marathon running
What investigations do you do to identify ferritin deficiency anaemia?
Endoscopy: -OGD -colonoscopy
Other investigations as directed by clinical symptoms
How do you treat ferritin deficiency?
Treat underlying cause
Oral iron supplementation e.g. ferrous sulphate 200mg tds
IV infusion of iron if available if required.
What is vitamin B12 ?
Where is it absorbed?
What does it require to be absorbed?
Vit B12 is a water soluble vit found in foods of animal origin (meat, liver, fish, dairy).
Terminal ileum
Requires intrinsic factor (produced by gastric parietal cells) to be absorbed.
What are the causes of vitamin B12 deficiency?
- Pernicious anaemia (autoimmune with auto-antibodies to either gastric parietal cells or intrinsic factor).
- Gastrectomy, ileal resection
- Malabsorption (crohns)
- Inadequate intake
- Nitrous oxide anaesthesia
What are additional clinical features of ferritin-deficiency anaemia?
premature greying of hair
jaundice
skin pigmentation
neuropathy
how do you treat vit B12 deficiency?
1mg hydroxycobalamin IM injections
initial 5 dose course. Regular 3 monthly injections as needed.
Where is folate found?
Folate is found in leafy green veg and is destroyed in cooking process.
What causes folate deficiency anaemia
Main cause is diet deficiency
other causes:
alcohol
folic acid antagonists
malabsorption i.e. coeliac disease
How do you treat folate deficiency
treat underlying cause
5mg PO folic acid (folate) daily for 4 months
What causes haemolytic anaemia?
increased destruction of RBCs
How can pts with haemolytic anaemia present?
jaundice, splenomegaly, gallstones
What are the two classifications of haemolytic anaemia?
Hereditary haemolytic anaemia
Acquired haemolytic anaemia
What are the causes of hereditary haemolytic anaemia?
Defects in RBC membrane e.g. hereditary spherocytosis
Defects in RBC metabolism e.g. G6PD deficiency, pyruvate kinase deficiency
Defects in haemoglobin e.g. thalassaemia, sickle cell anaemia
What are the causes of acquired haemolytic anaemia?
autoimmune haemolytic anaemia
infections e.g. malaria
drugs/chemicals e.g. dapsone, amyl nitrate
mechanical (i.e. prosthetic heart valves)
What causes thalassaemia?
abnormalities of globin chain synthesis
unbalanced synthesis of a and B globin chains results in precipitation of the chains with both mature RBCs (haemolysis) and RBC precursors (ineffective erythropoiesis)
What are the 2 types of thalaessemia?
alpha - thalassaemia
Beta - thalassaemia
What is a-thalassaemia?
reduced or absent synthesis of a-globin chains
What is B-thalassaemia?
Reduced or absent synthesis of B-globin chains.
What is thalassemia?
a severe anaemia with markedly reduced MCV.
it is caused by reduced or absent synthesis of globin chains.
What is thalassaemia faces?
The craniofacial features of thalassemia major patients include larger cheekbones, a rodent or “squirrel-like” face, a depressed nasal bridge, and a protruding maxilla.
BM expansion in children, especially in the skull bones, resulting in ‘hair-on-end’ radiographic appearance.
What is the treatment of thalassaemia?
blood transfusions
iron collation therapy
sometimes spleen removed if too large
What causes sickle cell anaemia?
abnormalities of globin chain structure.
There is a point mutation in B-globin gene causing a substitution of valine for glutamate in the B-globin chain. The resulting altered Hb is called HbS.
HbS is insoluble in deoxygenated state and its globin chains crystallise and become rigid taking their sickle shape.
What is a vaso-occlusive crisis? (sickle cell anaemia)
triggered by cold, hypoxia, GA, infection, dehydration.
bone pain, abdominal pain, dactylitis, cerebral infarction.
cold vessels constrict, block more easily
What is anaemia of chronic disease?
When is it seen:
a mild, non-progressive anaemia
seen in:
- malignant disease
- chronic inflammation
> infective (TB, infective endocarditis, osteomyelitis)
> non-infective (RA, SLE, Crohns, sarcoidosis, other CT diseases)
What is the pathogenesis of anaemia of chronic disease? (3)
- Reduced release of iron from BM stores to the plasma
- Inadequate erythropoiesis in response to anaemia
- Reduced RBC survival
What is the treatment of anaemia of chronic disease
treat underlying disease
What is aplastic anaemia?
What is pancytopenia?
disorder of stem cells resulting in pancytopenia.
pancytopenia = deficiency of all three cellular components of blood (RBC, WBC, platelets)
results in anaemia, thrombocytopenia (low platelet count) and leucopenia (low WBCs)
What are the hereditary causes of aplastic anaemia?
fanconi anaemia
What are the acquired causes of aplastic anaemia?
usually autoimmune, triggered by:
- drugs/chemicals e.g. cytotoxics i.e. chlorombucil, benzene, NSAIDS, choloramphenicol, carbimaxole, chlorpromazine, phenytoin.
- infections e.g. TB, viruses (Hepatitis, HIV, EBV, parovirus
- irradiation.
